persuasive
This argument is wholly unpersuasive.
In the end we found this an unpersuasive argument.
The defendant maintained that he was trying to flee; the court found this argument unpersuasive, reasoning that he led officers on a dangerous, high-speed car chase.
The trial judge will dismiss the evidence as unpersuasive.
This was an interesting, if unpersuasive, comment.
The novel's protagonist is a deeply unpersuasive hero.

SMART Vocabulary: related words and phrases

Urging & persuading
ambulance-chasing
argumentation
badger
be/go on at someoneidiom
blag
blagger
get (something) through (to someone)
go on
hortatory
hustle
incitation
incitement
jockey
sucker
sway
uncoerced
unconvinced
unpersuaded
unsalable
unsaleable